IMPROVEMENTS IN OR RELATING TO THE MANUFACTURE OF

专利名称：IMPROVEMENTS IN OR RELATING TO THE

MANUFACTURE OF EXTRUSION DIES

发明人：FELDCAMP, Edward G.申请号：EP99957030.2申请日：19990608公开号：EP1119424A1公开日：20010801

摘要：An extension die comprises a zero bearing die cavity (12) having a shape

corresponding to the cross-sectional shape of the required extrusion. In order to controlflow of the extrusion material through the cavity, a preform chamber (17) is providedwhich communicates with the die cavity but is of greater area. The depth and/or width ofthe preform chamber varies in different regions thereof, the dimensions of each regionbeing related to the dimensions and position of the corresponding region of the diecavity (12). In use, extrusion material passes through different regions of the preformchamber at different velocities, such that the material subsequently passes through allregions of the die cavity itself at substantially uniform velocity. The depth of the preformchamber is not greater than about 5 mm, and may be of any smaller depth, down to lessthan about 0.5 mm. Notwithstanding its very small depth, the preform chamber allowsaccurate control of the velocity of the extrusion material while at the same time allowinga high velocity of extrusion to be maintained.

申请人：Ailsa Investments Limited

地址：Victory House,Prospect Hill,P.O. Box 104 Douglas,Isle of Man IM1 1EQ GB

国籍：GB

代理机构：Bailey, Richard Alan

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